We randomly assigned 4589 healthy nulliparous women who were 13 to 21 weeks pregnant to receive daily treatment with either 2g of elemental calcium or placebo for the remainder of their pregnancies. Calcium supplementation did not significantly reduce the incidence or severity of preeclampsia or delay its onset. Additional analyses utilizing the study database and specimen repository are being performed. During FY05 papers were published on urinary placental growth factor and the risk of preeclampsia and on 24-hour urine insulin as a measure of hyperinsulinemia / insulin resistance in preeclampsia. Several important large studies on angiogenic factors in preeclampsia, gestational hypertension, and intrauterine growth restriction are underway.